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Elden [556K]
2 years ago
5

Describe why the periodic table needed to be reordered in 1913.

Chemistry
1 answer:
Norma-Jean [14]2 years ago
7 0

Answer:

1913. Henry Moseley determined the atomic number of each of the known elements. He realized that, if the elements were arranged in order of increasing atomic number rather than atomic weight, they gave a better fit within the 'periodic table'.

Explanation:

GOO

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Balance this equation<br> _Al +_HCI --&gt; _H2 +_AICIz
kumpel [21]

2Al+6HCl⇒3H₂+2AlCl₃

<h3>Further explanation </h3>

Equalization of chemical reaction equations can be done using variables. Steps in equalizing the reaction equation:  

• 1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c etc.  

• 2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index between reactant and product  

• 3. Select the coefficient of the substance with the most complex chemical formula equal to 1  

Reaction

Al+HCl⇒H₂+AlCl₃

  • Give coefficient

aAl+bHCl⇒cH₂+AlCl₃

  • Make equation

Al, left=a, right=1⇒a=1

Cl, left=b, right=3⇒b=3

H, left=b, right=2c⇒b=2c⇒3=2c⇒c=3/2

the equation becomes :

Al+3HCl⇒3/2H₂+AlCl₃ x2

2Al+6HCl⇒3H₂+2AlCl₃

5 0
2 years ago
A radioactive material, with half-life of six months, has 100 thousand unstable nuclei.
goldfiish [28.3K]

Answer:

See Explanation

Explanation:

Given that;

N/No = (1/2)^t/t1/2

Where;

No = amount of radioactive isotope originally present

N = A mount of radioactive isotope present at time t

t = time taken

t1/2 = half life

N/1000=(1/2)^3/6

N/1000=(1/2)^0.5

N = (1/2)^0.5 * 1000

N= 707 unstable nuclei

Since the value of the initial activity of the radioactive material was not given, the activity of the radioactive material after three months is given by;

Decay constant = 0.693/t1/2 = 0.693/6 months = 0.1155 month^-1

Hence;

A=Aoe^-kt

Where;

A = Activity after a time t

Ao = initial activity

k = decay constant

t = time taken

A = Aoe^-3 *0.1155

A=Aoe^-0.3465

3 0
3 years ago
Does brainy work with out Wi-Fi?​
nikitadnepr [17]

Answer:

No it does not i have tried it once before and it would not load for me and it froze the whole page site. But it might be different for you...

Explanation:

6 0
3 years ago
Read 2 more answers
A solution consists of 35.00 g of CuSO4 dissolved in 250.0 mL of water. The molar mass of Cu is 63.55 g/mol the molar mass of S
slamgirl [31]

The molarity of a solution that contains 35.00 g of CuSO4 dissolved in 250.0 mL of water is 0.88M.

<h3>How to calculate molarity?</h3>

The molarity of a solution can be calculated using the following formula:

Molarity = no of moles/volume

According to this question, a solution consists of 35.00 g of CuSO4 dissolved in 250.0 mL of water.

no.of moles of CuSO4 = 35g ÷ 159.6g/mol

no. of moles of CuSO4 = 0.22 moles

Therefore; molarity of CuSO4 solution is calculated as follows:

M = 0.22 ÷ 0.25

M = 0.88M

Therefore, the molarity of a solution that contains 35.00 g of CuSO4 dissolved in 250.0 mL of water is 0.88M.

Learn more about molarity at: brainly.com/question/12127540

6 0
2 years ago
How many grams are in 6.4 moles of so2
maw [93]

6.4mole•64.06g/1mole=409.98g

4 0
2 years ago
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